Decomposition of uric acid in blood

GAROT [1926] showed that the uric acid content of dog's blood falls considerably after digestion with "pancreatin"; this effect he ascribed to the presence of uricase in the blood of these animals.Flatow [1926] found that uric acid undergoes oxidation if added to blood, and that this process is greatly accelerated by passing air through the mixture.The uricolytic agent in this case was, according to this author, a substance which he termed "uricoid."Up to the present, no incontrovertible evidence has been adduced for the existence of uricase in the blood of any mammal, and the nature of the substance producing uricolysis is therefore still problematical.Biltz and Schauder [1923] and Piaux [1924] showed that a number of substances exist which catalyse the oxidation of uric acid, the most important being such metals as iron, copper, manganese.Since an iron-containing substance, haemoglobin, is present in blood, the possibility arose that this was the factor responsible for the oxidation of uric acid in blood.Experiments will be described in this paper having as their object the elucidation of the nature of the catalyst in question and of the action of haemoglobin upon uric acid. EXPERIMENTAL.A. Determination of uricolytic agent.Horse blood was collected at slaughter-houses, and potassium oxalate added immediately to prevent clotting.It was used generally within about 6 hours of shedding.The uricolytic powers of whole blood, blood-plasma, erythrocytes, boiled erythrocytes, stromata and haemolysed corpuscles free from stromata were determined separately.Two types of determination were made.In one, uricolysis was determined in bottles through which a feeble stream of oxygen was passed, whilst in the other determinations were made in stoppered flasks.In all cases 50 cc. of plasma, erythrocyte suspension, etc., were taken, and 20 cc. of lithium urate solution together with 20 cc. of water were added,